1. Field of the Invention
The present invention relates to a remote controlling system, an electronic device, and a controlling method of operating electronic devices with remote controllers.
2. Description of the Related Art
As an user interface that operates an electronic device (eg, television receiver), remote controllers have been widely used. As remote controllers, infrared remote controllers using an infrared communication system have become common. For example, multi remote controllers that can operate a plurality of types of electronic devices made by a plurality of manufacturers and learning remote controllers that receive infrared light codes from a source remote controller, analyze them, and store the analyzed codes have been commercialized.
Recently, as electronic devices operated with infrared remote controllers, flat panel television receivers (hereinafter, sometimes referred to as flat panel TVs) that use a display panel (eg, liquid crystal panel or plasma display panel (PDP)) are becoming common. Flat panel TVs, however, may radiate light having the similar wavelength to that of infrared signals emitted from infrared remote controllers.
In this case, when the power of the flat panel TV is turned on, if light radiated from the display panel enters the light receiving section of the flat panel TV, the light interferes with infrared signals emitted from the infrared remote controller. As a result, it becomes difficult to operate the flat panel TV with the remote controller. In particular, flat panel TVs using a PDP may radiate light having the similar wavelength to that of infrared signals.
As a method of solving such a problem, a method of disposing an optical filter that shuts out light having the similar wavelength to that of infrared signals emitted from the infrared remote controller on the light receiving section of the flat panel TV is known. In addition, if light having the similar wavelength to that of infrared signals is radiated, a method of disposing an optical filter that shuts out light having the wavelength on the entire display panel is known.
However, if such an optical filter is disposed on the light receiving section or the entire display panel, the cost of the electronic device will adversely increase.
In such a situation, recently, radio remote controllers using the Industrial, Scientific and Medical use (ISM) band (eg, 2.4 GHz band) radio communication system have attracted attention (hereinafter, they are referred to as radio remote controllers). Since the radio remote controller transmits signals to the electronic device by radio communication, light radiated from the display panel of the electronic device does not interfere with signals transmitted from the remote controller. Thus, it is not necessary to dispose the optical filter on the light receiving section or the entire display panel of the electronic device.
The radio remote controller have features of which it can control an electronic device even if there is an obstruction therebetween and can control the electronic device without pointing itself to the electronic device.
Technique about a radio remote controller using radio communication system is described in the following document disclosed as Japanese Patent Application Laid-Open No. 2002-16988 Publication.